Metamorphic Rocks - (Marble, Slate, and Schist)Metamorphic rocks are formed when magma (molten rock) is pushed upwards from the earth's core into overlying rocks. Unlike a volcanic eruption, the magma does not erupt through the surface but cools deep within the earth. These rocks are formed by the effects of high heat and high pressure.

Sedimentary Rocks - (Shales and Conglomerates)Rocks formed from sediment, precipitation from solution (concretion or crystalization), or the products of organisms. Examples: sandstone, rock salt, coal, and carbonates. Shales and sandstones are recycled rocks: existing rocks are eroded by rivers or the sea to form sand and mud. These deposits are then compressed to form a new rock.

Igneous Rocks - (Volcanic rocks like basalt, diabase, and granites)Rocks formed from hot molten material which cools on the surface of the earth.